Thanks Daniel!
I "think" I finished the install today. It was kind of traumatic. Homebrew got hidden somewhere and seems to work but I still can't find it. One final issue- I can only get afni to open from terminal if I use "open afni" as a command- just "afni" does not work. is this normal? also it gave me a lot of warnings (the "detached from terminal" one was what worried me the most):

[a-c1mmr3kndv30:~] vanheckea% /Users/vanheckea/abin/abin/afni ; exit;

Thanks go to P Taylor for great efforts

Initializing: X11.
++++++++ IMAGE SAVE SETUP WARNINGS ++++++++
++ Can't find program mpeg_encode for Save to MPEG-1
++ Can't find program cjpeg for Save to JPEG
++ Can't find program ppmtogif AND/OR ppmquant for Save to GIF
++ Can't find program ppm2tiff OR pnmtotiff OR pamtotiff for Save to TIFF
++ Can't find program ppmtobmp for Save to BMP
++ Can't find program pnmtopng for Save to PNG
++ Some of the missing image Save programs are in
++ the netpbm software package, which is freeware.
++ The 'fink' package at [fink.sourceforge.net]
++ is a way to get the netpbm programs for OS X; *OR*
++ Netpbm can be found at [netpbm.sourceforge.net]
++ To disable these warnings, set environment
++ variable AFNI_IMSAVE_WARNINGS to 'NO'.
+++++++++++++++++++++++++++++++++++++++++++
. Widgets.
++ WARNING: Can't find TTatlas+tlrc or TTatlas.nii.gz dataset for 'whereami'!
++--------- See [afni.nimh.nih.gov]
..... Input files:
** Searching subdirectories of './' for data
** No datasets or sessions input -- Dummy dataset created.
Time series = 0 files read
Plugins = 0 libraries read
** Your Unix path must include the AFNI binary directory
** OR you must setenv AFNI_PLUGINPATH to that directory!
++ AFNI is detached from terminal.
logout

[Process completed]

Does this look ok? Afni seems to still "work."

Thank you so much!!
Best,
Amy